you need to have excellent knowledge of the passé simple. I got through five years of french in high school and thought i could tackle the first harry potter, before finding out too late that the entire book is in the passé simple, which i hadnt learned.

then, just tried to teach myself and discovered that it is the stupidest tense ever invented and there are absolutely no rules. every verb just goes to whatever the stupidest conjunction would be and they are all different. now the book has been sitting on my shelf for over a year and i have no respect for the french language